Many corporations store a large percentage of their corporate information on large host systems, such as mainframes. The corporations have made substantial investments in creating the information and on maintaining the host systems to provide continuous access to the information at all times. Any changes that affect the host systems are scrutinized to determine whether the change is economical.
With the increasing popularity of the Internet, many corporations are evaluating how best to provide their host-stored corporate information and business logic to new customers residing on the World Wide Web (the Web). The corporations face the challenge of balancing their existing investments in their host systems with their desire to extend their corporate business by using new delivery platforms and the Internet.
There have been various proposed methods for providing information residing on a host system to customers through the Internet, in particular, using the Web. A typical solution involves adding new software code on the host system that interfaces with Web-based users. One disadvantage to this approach is that a skilled programming expert must first write the software code. The software code is then loaded and tested on the host system. During this process, the host system is taken off-line and is unavailable for processing corporate transactions. In addition, any maintenance of the newly created software code also requires the host system to be taken off-line. Taking the host system off-line in a business that depends heavily on the information results in a huge financial loss.
Another approach is to use component object modules (COM). For this approach, the client application provides the presentation layer for the application or the data. The client application may be an Active Server Page, a Visual Basic (VB) application, or a Microsoft Office application that can call a Microsoft Transaction Server (MTS) component. The MTS component is a COM object that provides the functionality for the mainframe transaction process (TP) as a COM interface method. Therefore, the MTS component contains the transaction logic for processing the component. A disadvantage of this approach is that the host code must be accessible at the client and the mappings are one-to-one.
Another approach uses a terminal emulator to access corporate information stored on a host system. The terminal emulator navigates the host displays to obtain the desired information. A disadvantage of this approach is that navigating through each of the displays on the host system is very slow. Another disadvantage is that each Web-based user that wants access to the information on the host system must have a logical terminal. A logical terminal requires the host system to allocate resources (i.e., memory) for the logic terminal. Because this approach requires resources from the host system, this approach only provides limited scalability for additional Web-based users. Typically, approximately 250 users have access to the corporate information at one time. The number of Web-based users supported, of course, depends on the memory resources of the host system.
Given the shortcomings of these approaches, there is a need for a method of providing access to information residing on a host system that does not require additional software programming and testing on the host system, does not require additional memory resources of the host system and that is scaleable to offer access to many Web-based users.